Sigma 28mm 2.8

[Mrpinks]

hi

i have just bought a sigma 28mm f2.8 mini wide II on a canon FD mount and have used an adapter to pop it onto my eos 550d.

Slight problem is that I have taken some shots and it seems to have a focal range of about 45mm if lucky. I thought that with this lens I would be able to take some more landscape shots but looks impossible, is this right or is there something I am doing wrong? Is it to do with the depth of the adaptor?

cheers

 

[BBbuilder467]

hi

i have just bought a sigma 28mm f2.8 mini wide II on a canon FD mount and have used an adapter to pop it onto my eos 550d.

Slight problem is that I have taken some shots and it seems to have a focal range of about 45mm if lucky. I thought that with this lens I would be able to take some more landscape shots but looks impossible, is this right or is there something I am doing wrong? Is it to do with the depth of the adaptor?

cheers

When you adapt the 28mm lens, it's no different than 28mm with the original lens.

18mm with the 1.6x crop would seem like 28mm in full frame.

 

[apathyman]

hi

i have just bought a sigma 28mm f2.8 mini wide II on a canon FD mount and have used an adapter to pop it onto my eos 550d.

Slight problem is that I have taken some shots and it seems to have a focal range of about 45mm if lucky. I thought that with this lens I would be able to take some more landscape shots but looks impossible, is this right or is there something I am doing wrong? Is it to do with the depth of the adaptor?

It's nothing to do with the adapter. A 28mm lens on an APC-C sensor camera will have the same field of view as a (28 x 1.6 = 45)mm lens on a full frame camera. Putting the lens on an adapter doesn't change that.

As BBbuilder said, to get the field of view that a 28mm lens gives on full frame, your 550D would need something like an 18 mm lens.

Cheers

Brian

 

[Mrpinks]

Thanks guys, so it's normal to just be able to focus that closely on a subject with that lens?

I was hoping to be able to take some shots with a longer depth of field than that but sounds like it's not going to happen.

On my nifty fifty I can, don't suppose anyone can help explain why I can't with this lens?

Thanks. Andy

 

[apathyman]

Thanks guys, so it's normal to just be able to focus that closely on a subject with that lens?

I was hoping to be able to take some shots with a longer depth of field than that but sounds like it's not going to happen.

On my nifty fifty I can, don't suppose anyone can help explain why I can't with this lens?

I think you need to explain what you mean more clearly.

The replies to your first post were dealing with the field of view of the lens on your camera compared with the field of view on full frame, so I'm not clear on what you mean by 'focus that closely on a subject' and 'on my nifty fifty I can'.

Cheers

Brian

 

[Mrpinks]

Sorry, still new to all this.

I bought this lens as I thought I could use it as a fixed prime for either some portraits or landscapes. However when I use it I can't manage to get anything in focus that is more than 45mm away. No matter what appetite I use. So great for close up macro but is that right? I thought that at a higher apature I would be able to get more in focus but it all comes out blurry!

I have the modern 50mm canon prime lens that fits my 550d and I can take brilliant portraits on that but this lens isn't letting me do that, is that right or am I doing something wrong?

Hope that helps Brian, thanks for your help!

 

[apathyman]

Sorry, still new to all this.

I bought this lens as I thought I could use it as a fixed prime for either some portraits or landscapes. However when I use it I can't manage to get anything in focus that is more than 45mm away. No matter what appetite I use. So great for close up macro but is that right? I thought that at a higher apature I would be able to get more in focus but it all comes out blurry!

I have the modern 50mm canon prime lens that fits my 550d and I can take brilliant portraits on that but this lens isn't letting me do that, is that right or am I doing something wrong?

Hope that helps Brian, thanks for your help!

OK - that makes the issue more clear.

What sort of adapter is it? Does it have a glass element lens as part of the construction or is it a simple cylindrical tube?

If it has no glass element, then it is basically an extension tube, which would explain why you can't focus at long distances. Extension tubes are for macro work.

Here's an example of a glassless adapter :

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www.ebay.com

If it does have a glass element then either the adapter or the lens is faulty - perhaps the focus ring on the lens is slipping and not moving the lens over its full focus range.

Here's an example of an adapter with a glass lens:

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www.bhphotovideo.com

Cheers

Brian

 

[Mrpinks]

Hi Brian,

Thanks, yes I have the glass less converter. I git this one as I though more optics would downgrade image quality not realising that the extra distance / depth of the adapter would cause problems!

What would you recommend I do? Would the lens work as it should do if I bought an adapter with glass on it? Or will the extra glass cause problems?

Seems like the old FD fittings are awkward!

Cheers

Andy

 

[apathyman]

Hi Brian,

Thanks, yes I have the glass less converter. I git this one as I though more optics would downgrade image quality not realising that the extra distance / depth of the adapter would cause problems!

What would you recommend I do? Would the lens work as it should do if I bought an adapter with glass on it? Or will the extra glass cause problems?

Yes, the lens should work OK with a glassed adapter. I don't have any personal experience with these so I can't say what effect the glass will have on image quality. If it's a quality adapter, there probably wouldn't be much deterioration.

It's worth noting, though, that the Fotodiox adapter I linked to previously increases the focal length of the lens by a factor of 1.4, so the 28mm lens plus adapter would have a focal length of about 40mm.

There are other brands. This one has a focal length increase of 1.25:

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www.bhphotovideo.com

Cheers

Brian